In the related art, an eye gaze detection technology for detecting the user's eye gaze or the line of sight is used in an input interface, determination of a user's state, or the like. For example, the input interface is used as a technology for detecting the user's eye gaze as data and operating icons on a screen of a computer by using the detected eye gaze data. In addition, the determination of the user's state is used in a technology for detecting a user's eye gaze while driving a vehicle and then outputting an alarm by determining whether or not a driver looks aside while driving.
Particularly, the eye gaze detection technology using a non-contact type camera or the like reduces an operation load on a user and thus is widely used. For example, there is a corneal reflection method for detecting an eye gaze by extracting a corneal reflection area of the user from an image captured by a camera. As an application technology for the above technology, a technology for selecting an optimal corneal reflection area by removing an area acquired by the reflection of a spectacle lens in a plurality of candidates of corneal reflection areas is disclosed (for example, refer to Japanese Laid-open Patent Publication No. 2012-239550).
In addition, as a technology related to the eye gaze detection technology, the following technologies are disclosed. A technology for detecting and tracing an eye and an eye blink from an image of a user's face (for example, refer to Japanese Laid-open Patent Publication No. 2001-43382).
A technology for extracting a partial image which is considered to include a face image from a target image based on an edge image extracted from the target image, and determining whether or not the extracted partial image includes the face image by referring to a learning dictionary that holds learning information for identifying the face image and a non-face image (for example, refer to Japanese Laid-open Patent Publication No. 2003-44853).
A technology for detecting a user's eyeball from the target image by moving a template image in which the eyeball is modeled by using genetic algorithms to each portion on the target image which is the image of a user's face to perform template matching (for example, refer to Japanese Laid-open Patent Publication No. 2013-45151).
A technology for more accurately extracting a contour of an eye from an input face image of a user by using a two-dimensional template (for example, refer to Japanese Laid-open Patent Publication No. 2001-22933).
A technology for detecting a reflection illumination part of the glasses from a captured image of a user wearing glasses (for example, refer to Japanese Laid-open Patent Publication No. 2001-167284).